Surfactants are often added to laundry detergent compositions. Often these provide a cleaning benefit to fabrics washed with the laundry detergent composition.
In the case of granular laundry detergent compositions, surfactants can be incorporated into the granules during spray-drying, or agglomeration for example, or they can be post-added to the granules. If they are post-added, they are often sprayed onto the detergent granules. However, this post addition spray-on can result in the formation of large granules, due to uneven distribution of the surfactant, i.e. the surfactant tends to form large droplets that stick to the detergent granules and result in the formation of large granules.
The formation of these large granules is undesirable to consumers, who prefer smaller granules. Consumers associate large granules with slow dissolution and poor cleaning performance.
Thus, there is a need in the art for a method to make a granular detergent composition that comprises post-added surfactant and that has a consumer acceptable appearance.
The Inventors have surprisingly found that if an emulsion is firstly made of the surfactant ahead of spraying onto the spray-dried particles, the problem of large granule formation is reduced.